Wellhead apparatus



Oct. 20, 1964 ca. A. NICHOLAS 3,153,549

WELLHEAD APPARATUS Filed Dec. 2, 1959 5 Sheets-Sheet 1 Geo/ye A. A/m/zo/a:

INVENTOR.

Oct. 20, 1964 G. A. NICHOLAS 3,

WELLHEAD APPARATUS Filed Dec. 2, 1959 3 Sheets-Sheet 2 660/ e A. Mafia/0a 23 y INVENTOR.

Oct. 20, 1964 G. A. NICHOLAS WELLHEAD APPARATUS 3 Sheets-Sheet 3 Filed Dec. 2, 1959 J m mm 3 M Q 4 A e m w B United States Patent 3,1535% WELLHEAD APPARATUS George A. Nicholas, Houston, Tex, assignor to (Iameron iron Works, Ind, Houston, Tex a corporation of Texas Fiied Dec. 2, 19%, Ser. No. 856,795 3 Claims. (Cl. 285137) This invention relates broadly to wellhead apparatus for suspending two or more tubing strings in side-by-side relation within the well so as to produce a separate zone of the well through each string. More particularly, it relates to improvements in apparatus of the general type disclosed in a copending application, Serial No. 679,621, now Patent No. 3,004,778, which is assigned to the assignee of the present application. By means of the apparatus of this earlier application, hangers for the string can be lowered beneath and then returned to supported positions within the bore of a tubing head in order to permit the performance of certain operations common to the completion of a well, such as in setting and unsetting a production packer, washing drilling mud out of the bottom of the well, and taking a strain on the string to place it in tension.

In the apparatus of the earlier application, each hanger is separately supported from a ram mounted on the tubing head for radial movement between positions extended into the bore to support the hanger and retracted therefrom to permit the hanger to be raised and lowered. More particularly, each hanger is substantially sector-shaped and has a seat about an intermediate portion of its curved side to engage a seat on the inner ends of the rams. Obviously, a ram and hanger is provided for each string to be suspended.

Although this earlier invention represents a considerable advancement over the prior art, the particular apparatus illustrated in the application has several shortcomings. For one thing, as shown in the drawings of this earlier apparatus, the curved sides of the sectorshaped hangers are adapted to fit closely adjacent the bore of the tubing head so as to support packing for sealing between the hangers and the bore. On the other hand, the inside diameter of easing beneath the tubing head may vary a fairly substantial amount depending upon the weight of the casing. As a result, it may be found that the apparatus of the earlier application is not usable within the full range of such casing due to the inability of lowering its hangers into the heaviest casing.

Also, many production packers are of a tension type which require that a string be rotated in being connected thereto and disconnected therefrom. Obviously, the same sector-shaped hangers prevent this manipulation of the strings when supported within the bore of the tubing head.

An object of this invention is to provide apparatus of this general type which enables the use of a full range of easing weights as well as tension type production packers.

Another object is to provide such apparatus which also provides a larger seating area between the hangers and rams.

Still another object is to provide such apparatus having parts including the hangers of simplified construction.

Other objects, advantages and features of this invention will be apparent to one skilled in the art upon a consideration of the written specification, the attached claims and the annexed drawings.

In the drawings, wherein like reference characters are used throughout to designate like parts:

FIG. 1 is a half-sectional view of apparatus constructed in accordance with the present invention, wherein one ram is retracted from the bore of the tubing head and the hanger to be supported from it has been lowered within the bore beneath its supported position;

3,153,549 Patented Got. 20, 1964 FIG. 2 is a full sectional view of part of the apparatus of FIG. 1, with the hanger raised above its supported position;

FIG. 3 is a view similar to FIG. 2, but with the ram extended into the bore and the hanger, which is shown partially in section, lowered into supported position upon the ram;

FIG. 4 is another full sectional view of the apparatus, as seen along broken line 4-4 of FIG. 5, with a second hanger lowered into supported position upon another ram to suspend a second string alongside of the string suspended from the first-mentioned hanger, and with a sealing assembly in place for sealing between the hangers and the bore of the tubing head;

FIG. 5 is a cross-sectional view of the apparatus, taken substantially along broken line 5-5 of FIG. 4, the seat on the rightmost ram being shown in elevation for illustrative purposes; and

FIG. 6 is a perspective view of one of the rams removed from the tubing head.

Referring now in detail to the above-described drawings, the apparatus of the present invention comprises, as in the earlier application, a tubing head 10 having a bore 11 therethrough and a plurality of tubing hangers 22 disposable within the bore for suspending tubing strings 23 in side-by-side relation within the well (see FIG. 4). Also, a plurality of rams 24 are mounted on the head for movement between positions extended into the bore to support the hangers when so disposed and retracted from the bore to permit the hangers to be lowered beneath their supported positions, and then raised to a position for seating on the rams. However, in accordance with the novel aspects of the present invention, and as will be explained more fully hereinafter, the tubing hangers 23 are substantially cylindrically shaped so that they maybe rotated within the bore of the tubing head for connection to or disconnection from a production packer within the well. Also, since the hangers do not fit closely against the bore, they may be lowered into a full range of casing weights.

More particularly, each ram has a throat 41 opening onto its inner end and is counterbored at 41:: to provide a seat 43 about the throat, and each hanger has a seat 49 for seating upon the seat of a ram in its extended position and a radially reduced portion 42 beneath the seat over which the ram throat 41 will pass laterally as it is extended into the bore. Thus, as each string of tubing is lowered into the well on its hanger, the ram for supporting that hanger is retracted to permit the hanger to be lowered beneath its supported position, as shown in FIG. 1. Then, as the hanger is raised to a position above its supported position (FIG. 2), the ram is moved into its extended position to dispose its seat 43 beneath the hanger seat 4t) in such a way "that, as it is lowered, the hanger will be supported against both vertical and lateral movement (FIG. 3). With both hangers so supported, as shown in FIGS. 4 and 5, the two strings of tubing 23 are suspended within the well in side-by-side relation to produce from two separate zones therein. If for some reason, it should be desired to again lower and raise one or both of the hangers, this may be done by raising the hanger slightly above its supported position and then withdrawing the ram to permit the hanger to be lowered therepast. Of course, as in the case of the earlier application, three or more hangers and rams could be provided for suspending a similar number of strings.

When both hangers are supported, the space between them and the bore of the tubing head is closed off by a sealing assembly 45, as shown in FIG. 4. In accordance with this invention, the assembly comprises a sandwich of disc-shaped elements having a pair of openings 47 therein for disposal over the portions 48 of the hangers 22 above the rams and seatable upon a shoulder or seat 46 in the bore above the guideways 12 for the rams.

Referring now to the details of the drawings, and particularly PEG. 1 thereof, the flanged lower end of tubing head 19 is connected to the upper end of a casing head 14 by means of bolts 13 and sealed with respect thereto by a seal ring 15, all in a conventional manner. The lower end of the tubing head bore 11 is recessed at 16 to receive the upper end of a casing 11 supported from the casing head lid in a manner (not shown) well known in the art. As can be seen from FIG. 1, the inside diameter of the casing 17 forms at least a substantial continuation of the bore 11, although it might be somewhat smaller or larger than the bore depending on the casing weight.

Pressure control apparatus including a blowout preventer 13 is connected to the upper end of the tubing head to by means of bolts 19 and sealed with respect thereto by a seal ring 26, again in accordance with conventional practices. The bore 21 through the preventer forms at least a substantial continuation of the upper end of the tubing head bore 11 to permit the running of production packers and other apparatus on the tubing strings.

When, as illustrated, the apparatus of this invention is for use in dually completing a well through the two strings 23, the rams .24 will normally be received within guideways 12 formed in diametrically opposed bosses 25 of the tubing head. The outer ends of the guideways 12 are closed by means of bonnets 26 bolted as at 27 to the bosses and sealed pressure-d bt by means of llat metal gaskets 28 between the interfaces of the bosses and bonnets.

Each or" the rams 24 is substantially cyindrical in transverse cross section, as best shown in FIG. 6, for guidably sliding longitudinally within its similarly shaped guideway 12 between a position retracted from the here, as shown in each of FIGS. 1 and 2, and another position extended into the bore, as shown in each of FIGS. 3, 4 and 5. Each ram is reciprocated by means of a stem 29 carried by the bonnet and threadedly connected at its inner end 39 with the outer end of the ram. More particularly, a flange 31 on each stem is held by the bonnet against longitudinal movement, and each ram is held against rotation within its guideway by means of a pin 32 having an inner end which projects into the guideway for the ram to fit closely within a slot 33 extending along the side of the ram, as shown in FIG. 5. The stem is rotated in a desired direction by means of a non-circular part on its outer end to move the ram to which it is connected between extended and retracted positions. The outer end 34 of the slot 33 is so located as to position the ram against further inward movement beyond its extended position for supporting a hanger.

A slot 3'5 extending along the lower side of the ram connects its inner and outer ends for draining any material which might accumulate in the guideway behind the rams. Also, the rotatable stem 29 is sealed with respect to the bonnet by means of packing 36 carried by the bonnet and a gland nut 37 surrounding the stem.

Each hanger 22 comprises a mandrel which has an opening 38 extending axially therethrough and which is substantially cylindrical in cross section. The upper and lower ends of the opening 38 through each hanger mandrel are provided with female threads for connection with a handling joint 3% and the tubing 23 suspended therefrom, respectively. As well known in the art, the bandling join-t extends upwardly through the pressure control equipment for manipulation by suitable apparatus in raising and lowering the hanger to which it is connected.

The seat ll) on each hanger is formed by a downwardly and outwardly tapered circumferential surface on the lower end of the upper portion 48 of the mandrel. The throat ii opening onto the inner end of each ram is of a size to laterally pass the radially reduced portion 42 of the hanger beneath the seat as and the counterbore 41a is of a size to receive the upper portion 48 of the hanger above the seat The seat 43 on each ram is tapered corres ondingly to the hanger seat ill so that, when the latter is supported by the ram, it is held against lateral as well as vertical movement within the bore ill of the tubing head. More particularly, the throat ll of each ram is substantially sl-shaped so that the ram seat will engage with more than half of the hanger seat or about an arc thereof greater than thereby providing a maximum load bean area. As can best be seen from FIG. 5, each hanger is also held against lateral movement =y the portions of the counterbore 4101.

rue reduced portion d2 of the hanger beneath its seat is of a length at least sufficient to enable the ram throat to be laterally or it as the ram is extended with the h nger in the raised position of PEG. 2. As best shown l, the lower end or the hanger mandrel is enlarged at to provide the female threads for connecwith the 23 having an Ll). substantially the same the diameter of the mandrel opening 38. As best shown in l, the substantially cylindrical outer surface of the hanger mandrel permits the hanger to be lowers into and rotated in a casing It? having an ID. at east substantially the same as the bore 11 of the tubing cad, even when another hanger is already in place. Furherrnore, there is at least a slight space between the mandrel bore so th the hanger may be lowered into even the heaviest weight of casing.

With the rams retracted from the bore of the tubing head, the first of the tubing strings 23 may be run into the well upon its hanger 22. Normally, a production packer (not shown) will be supported on the first string in a position to seal oil the casing 17 above the lower of the two production Zones, opposite both of Which/the casing is perforated, to thereby confine the flow from such lower Zone into the first tubing string. This string will also carry another packer having a second opening in it and positioned above the first packer to seal off the casabove the upper zone. Thus, the second string may is run into the well and through the second opening in the upper packer to produce from the upper zone.

As previously mentioned, it may be necessary to lower and rotate the strings in setting the packers, or in washing mud out of the bottom of the Well or taking a strain on the tubing to place it in tension. In any case, when the first string 23 is run, its hanger 22 may be lowered beneath its supported position, as shown in FIG. 1, and then raised to the position of FIG. 2 wherein its seat 40 is disposed above the seat 43 on the ram. This permits the ram to be moved inwardly into extended position, as determined by engagement of the end 34 of the ram slot 33 with the inner end of the pin 32, to locate its seat 43 beneath the hanger seat 44). At this time, the hanger is lowered by means of the handling joint 39 to permit its seat it to land upon the seat 43 of the ram, whereby the hanger is then supported against vertical as well as lateral movement in the tubing head bore. The second string 23, which is shown on the left in each of FIGS. 4 and 5, is run into the well and supported from the other ram in the same manner as described above in connection with the first string.

As shown in FIG. 1, there are threads 54 on the opening 3% through each hanger for connection with a back pressure valve (not shown). These valves may be in place as the hangers are run on the handling joints 39. Alternatively, the handling joints may be removed when the hangers are supported within the bore to permit installation of the back pressure valves. in either case, the sealing assembly 55 is lowered through the preventer 18 and into the .bore 11 for seating upon the shoulder 46 about the bore. When the assembly is so seated, the openings 47 therethrough closely receive the upper portions 48 of the hanger mandrels and the outer periphery of the assembly is disposed closely adjacent the bore.

More particularly, this sealing assembly comprises a disc &9 of rubber or like sealing material disposed between upper and lower discs 50 and 51 of rigid material with the outer periphery of the upper plate being tapered at 52 for engagement by the inner tapered ends or" pins 53 mounted about the upper end of the tubing head. As shown in FIG. 4, these pins are threadedly and sealably received within the tubing head for movement radially inwardly of the tubing head bore. When the pin is moved inwardly against its tapered edge 52, the disc 50 compresses the disc 49 into sealing engagement between the hangers and head, as shown in FIG. 4.

Obviously, when the inner ends of the pins 52 are moved outwardly of the bore, the sealing assembly 45 may be inserted and removed. It will also be apparent that the landing of this assembly upon a shoulder in the bore of the tubing head avoids the imposition of the load of the pins upon the hangers and thus the rams.

With the back pressure valves and the assembly 45 in place to close the tubing bore, the pressure control equipment including the preventer 18 is removed and a Wellhead fitting, such as a master valve and Christmas tree (not shown), is connected above the tubing head. In accordance with conventional practice, the lower end of this valve may have recessed portions for fitting over the upper ends or" the hangers to seal thereabout and hold them against upward movement. In this respect, it will be noted that any appreciable upward movement of the hangers prior to disposal of the master valve thereover would .be prevented by engagement of the enlarged lower portion 44 of each hanger, which has an outer diameter at least substantially equal to that of the upper portion thereof, with the lower side of the throat 41 of its ram. With the wellhead fitting in place, the back pressure valves may be removed and the well completed.

From the foregoing it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth, together with other advantages which are obvious and which are inherent to the apparatus.

twill be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is h to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

The invention having been described, what is claimed is:

1. Wellhead apparatus, comprising a tubing head having a bore therethrough, a plurality of substantially cylindrically shaped tubing hangers disposable within the bore for suspending tubing strings in side-by-side relation within the well, a plurality of rams mounted on the head for movement along radii of the bore between positions extended into the bore to support the hangers against vertical movement when so disposed and retracted from the bore to permit the hangers to .be lowered beneath their supported positions, each hanger having a reduced portion and a downwardly facing annular seat thereabove, each ram having a substantially U-shaped throat opening onto its inner end to receive said reduced portion of the hanger to be supported thereby and a seat extending in an are about the throat more than for supporting a corresponding portion of the annular hanger seat and thereby holding said hanger in an upright position independently of each other hanger and independently of the bore through the tubing head, and means on the ram for holding the hanger against lateral movement when so supported.

2. Wellhead apparatus of the character defined in claim 1, wherein said holding means comprises complementary tapers on the ram and hanger seats.

3. Wellhead apparatus of the character defined in claim 1, wherein the holding means comprises a counterbore in the ram which receives a portion of the hanger above the hanger seat in the seated position of said hanger.

References Cited in the file of this patent UNITED STATES PATENTS 259,048 Richardson June 6, 1882 1,592,093 Foucault July 13, 1926 2,086,431 Penick July 6, 1937 2,286,105 Quinn June 9, 1942 2,830,665 Burns Apr. 15, 1958 2,934,148 Allaire Apr. 26, 1960 3,004,778 Williams Oct. 17, 1961 

1. WELLHEAD APPARATUS, COMPRISING A TUBING HEAD HAVING A BORE THERETHROUGH, A PLURALITY OF SUBSTANTIALLY CYLINDRICALLY SHAPED TUBING HANGERS DISPOSABLE WITHIN THE BORE FOR SUSPENDING TUBING STRINGS IN SIDE-BY-SIDE RELATION WITHIN THE WELL, A PLURALITY OF RAMS MOUNTED ON THE HEAD FOR MOVEMENT ALONG RADII OF THE BORE BETWEEN POSITIONS EXTENDED INTO THE BORE TO SUPPORT THE HANGERS AGAINST VERTICAL MOVEMENT WHEN SO DISPOSED AND RETRACTED FROM THE BORE TO PERMIT THE HANGERS TO BE LOWERED BENEATH THEIR SUPPORTED POSITIONS, EACH HANGER HAVING A REDUCED PORTION AND A DOWNWARDLY FACING ANNULAR SEAT THEREABOVE, EACH RAM HAVING A SUBSTANTIALLY U-SHAPED THROAT OPENING ONTO ITS INNER END TO RECEIVE SAID REDUCED PORTION 